Use of Ionized Fluid in Hydraulic Fracturing

ABSTRACT

A method and system for generating an ionized fluid, injecting the ionized fluid into fissures in a subterranean formation, pressurizing the ionized fluid, whereby the crystalline structure of a portion of the shale deposits located at the fissures are changed into suspended particles, whereby the depressurization of the ionized fluid forces the suspended particles out of the fissures, increasing the flow of hydrocarbons from those fissures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/229,320, filed Mar. 28, 2014, which is a continuation in part of U.S.application Ser. No. 14/095,346, filed Dec. 3, 2013, which is acontinuation of U.S. application Ser. No. 13/832,759, filed Mar. 15,2013, which is a continuation in part of U.S. application Ser. No.13/594,497 filed Aug. 24, 2012, which claims priority to U.S.Provisional App. No. 61/676,628, filed Jul. 27, 2012. This applicationclaims priority to all the previously listed applications and alsoclaims priority to U.S. Divisional application Ser. No. 13/753,310,filed on Jan. 29, 2013.

BACKGROUND OF THE INVENTION

The hydraulic fracturing of oil wells was started in the late NineteenForties as a means of oil well stimulation when trying to extend theeconomic life of a depleting oil well. Most oil wells, at that time,were driven vertically. The placement of shaped explosive charges, inthin wall casings, was limited to these explosive charges being placedin predetermined, hydrocarbon pay zones, and mostly in sand formations.The shaped explosive charges were ignited to create fissures or channelsin these zones. A mixture of pressurized water and sand is pumped intothe wellbore as a means of well stimulation.

This practice of well stimulation continues in vertically driven wellsto this day. It wasn't until Mitchell Energy, in the mid-nineteennineties utilized two newly developed technologies, changed the wayunconventional, insitu hydrocarbon shale could be produced economically.The first new technology utilized was the development of steerable andcontrollable drilling techniques that could change the direction of adrill bit going in a vertical direction and rotating it into ahorizontal direction. This rotation could be accomplished with areasonably short bending radius and the drill bit could then continue todrill horizontally for a considerable distance into the shale formation.

The second technology that was needed involved the development of higherpressure fracturing pumps that were capable of achieving water pressuresin the range of nine thousand to ten thousand pounds per square inchrange at the surface. The answer was the development of fracturing pumpsthat could achieve these pressure levels with positive displacements.Both technologies are essential for the economic extraction ofhydrocarbon gases and liquids in hard and soft shale formations.Companies today are producing gaseous and liquid hydrocarbons and usemostly chemical products to control the growth of micro-organisms. Thesecould eventually migrate into potable water aquifers.

Currently, it is common practice to kill micro-organisms that are in thewater mixture, either initially or insitu, by chemical or other types ofbiocides, so that the gaseous and liquid hydrocarbons that are trappedin the oil shale's matrix formation can flow freely into the channelsand fissures vacated by the flow-back water mixture. Also, the channelscreated by the fracturing process must be kept open by the proppantsthat are initially carried into the fissures in the fracture zones bythe injected water mixture. If the micro-organisms are not killed theywill multiply, rapidly; and, if they remain in the fissures, they willgrow and reduce or entirely block the flow of hydrocarbons from thesefissures. Another significant micro-organism type problem is thepossible presence of a strain of microbes that have an affinity forseeking out and digesting any free sulfur or sulfur bearing compoundsand producing hydrogen sulfides that must be removed from any productgas stream because it is a highly dangerous and carcinogenic material.All these types of micro-organisms must be destroyed if this type ofproblem is to be avoided.

In addition to the possibility of micro-organisms multiplying andblocking the flow of hydrocarbon product, the presence of dissolvedsolids in the water solution can also be a problem in the injected watermixture. They can deposit themselves as scale or encrustations in thesame flow channels and fissures. These encrustations, if allowed to bedeposited in these channels, will also reduce or block the flow ofhydrocarbons to the surface. In order to avoid this condition, attemptsare made in current industry practice to have the dissolved solidscoalesce and attach themselves to the suspended or other colloidalparticles present in the water mixture to be removed before injection inthe well; however, those efforts are only partly effective. See, e.g.Denny, Dennis. (2012 March). Fracturing-Fluid Effects on Shale andProppant Embedment. JPT. pp. 59-61. Kealser, Vic. (2012 April).Real-Time Field Monitoring to Optimize Microbe Control. JPT. pp. 30,32-33. Lowry, Jeff, et al. (2011 December). Haynesville trial wellapplies environmentally focused shale technologies. World Oil. pp.39-40, 42. Rassenfoss, Stephen. (2012 April). Companies Strive to BetterUnderstand Shale Wells. JPT. pp. 44-48. Ditoro, Lori K. (2011). TheHaynesville Shale. Upstream Pumping Solutions. pp. 31-33. Walser, Doug.(2011). Hydraulic Fracturing in the Haynesville Shale: What's Different?Upstream Pumping Solutions. pp. 34-36. Denney, Dennis. (2012 March).Stimulation Influence on Production in the Haynesville Shale: A PlaywideExamination. JPT. pp. 62-66. Denney, Dennis. (2011 January). TechnologyApplications. JPT pp. 20, 22, 26. All of the above are incorporatedherein by reference for all purposes.

In recent years, the oil industry has tried to develop a number of waysto address these concerns. The use of ultra violet light in conjunctionwith reduced amounts of chemical biocide has proven to be only partiallyeffective in killing water borne micro-organisms. This is also true whenalso trying to use ultra-high frequency sound waves to killmicro-organisms. Both these systems, however, lack the intensity andstrength to effectively kill all of the water-borne micro-organisms withonly one weak short time residence exposure and with virtually noresidual effectiveness. Both systems need some chemical biocides toeffectively kill all the water borne micro-organisms that are in water.Also, some companies use low-frequency or low-strength electro-magneticwave generators as biocide/coalescers; however, these too have proven tobe only marginally effective.

Therefore, an object of further examples is to economically address andsatisfactorily resolve some of the major environmental concerns that areof industry-wide importance. Objects of still further examples are toeliminate the need for brine disposal wells, eliminate the use of toxicchemicals as biocides for micro-organism destruction, or for scaleprevention, and the recovery of all flow-back or produced water forreuse in subsequent hydraulic fracturing operations. Examples of theinvention provide technically sound and economically viable solutions tomany of the public safety issues that have concerned the industry inhydraulic fracturing.

SUMMARY OF EXAMPLES OF THE INVENTION

In at least one example, the specific pulse imparted has the followingcharacteristics: variable, ultra-high frequencies in the range ofbetween about 10 and 80 kHz. Other pulses having sufficient frequency tokill the micro-organisms present in water and to cause dissolved solidsto coalesce will occur to those of skill in the art and may depend onthe specific properties of the water at a particular well. The pulsewill generally rupture the cells of the micro-organisms.

In a more specific example, method further comprises slowing the flowrate in the plurality of flows of water to be less than the flow rate ofthe flow of water with suspended solids. Slowing the flow rate allowsfor greater residence time during the step of generating positivecharge. That increases the amount of positive charge in the water whichis considered to be beneficial for killing microbes in the water and forproviding residual positive charge for a period of time when the waterhas been injected into a geologic formation from which hydrocarbons areto be produced. The presence of positive charge in the waters' geologicformation is believed to have benefits in reducing the presence ofvarious flow-reducing structures in the formation.

In a further specific example, the method generating positive charge inthe flows of water comprises treating each of the plurality of flows ofwater with electromagnetic flux.

In still a further example, the majority of the suspended solids areless than about 100 microns. In some such examples, substantially allthe suspended solids are less than about 100 microns. In a more limitedout of examples, the majority of the suspended solids are less thanabout 10 microns. And in still a more limited set of examples,substantially all the suspended solids are less than about 10 microns.By reducing the size of the suspended solids, it becomes possible topass the water through devices that are practical for generatingpositive charge in the water at a reasonable cost by using, for example,stainless steel conduits when the suspended solids approach 100 micronsand softer materials (for example, PVC) as the solids approach 10microns and smaller.

In a further example, the means for generating positive charge comprisesmeans for treating each of the plurality of flows of water withelectromagnetic flux. At least one such example, the means for treatingeach of the plurality of flows of water with electromagnetic fluxcomprises: a pipe; and at least one electrical coil having an axissubstantially coaxial with the pipe. In some such examples, the pipeconsists essentially of non-conducting material. In some such examples,the pipe consists essentially of stainless steel. In a variety ofexamples, there is also provided a ringing current switching circuitconnected to the coil. In some such examples, the ringing currentswitching circuit operates in a full-wave mode at a frequency betweenabout 10 kHz to about 80 kHz.

In still a further example, the means for co-mingling comprises amanifold having input ports for a plurality of flows ofpositively-charged water and an output port. In one such example, themeans for co-mingling further comprises a well fracturing water andproppant blender. In a variety of examples, the majority of thesuspended solids are less than about 100 microns. In some such examplessubstantially all the suspended solids are less than about 100 microns.In a more limited set of examples, the majority of the suspended solidsare less than about 10 microns. In an even more limited set of examples,substantially all the suspended solids are less than about 10 microns.

Examples of the inventions are further illustrated in the attacheddrawings, which are illustrations and not intended as engineering orassembly drawings and are not to scale. Various components arerepresented symbolically; also, in various places, “windows” intocomponents illustrate the flow of material from one location to another.However, those of skill in the art will understand which components arenormally closed. Nothing in the drawings or detailed description shouldbe interpreted as a limitation of any claim term to mean something otherthan its ordinary meaning to a person of skill in the varioustechnologies brought together in this description.

In at least one example, a method for increasing hydrocarbon productionfrom a subsurface formation, comprises: generating ionized fluid,pumping the ionized fluid from a surface location into at least onesubsurface location in a hydrocarbon well, pressuring the ionized fluidat the at least one subsurface location, depressurizing the ionizedfluid at the perforated location, wherein at least a portion of theionized fluid returns to the surface location containing suspendedmaterials. In another example, the method further comprises perforatingat least one subsurface location.

In at least one such example, the method further comprises fracturing inat least one subsurface location. In yet another example, the methodfurther comprises isolating at least one subsurface location from atleast one portion of the hydrocarbon well.

In yet another example, the method, wherein said ionized fluid inhibitscorrosion of the hydrocarbon well. In a further example, the methodwherein the ionized fluid composition comprises at least fifty percentwater by volume.

In another example, the ionized fluid comprises positively chargedwater. In still a further example, the method further comprises mixingthe ionized fluid with a proppant.

According to a further example, the method wherein the ionized fluid isgenerated by exposing water to electromagnetic fields of influence. Inyet another example, the method wherein the electromagnetic field ofinfluence is pulsed at a full wave of up to three hundred and sixtytimes per second. In another example, the method wherein theelectromagnetic field of influence is pulsed at a full wave of more thaneighty times per second.

In yet another example, the method wherein the suspended particlesinclude calcium based suspended particles.

In still a further example, the method further comprises recycling aportion of the flowback fluid from the well. In another example, themethod further comprises recycling a portion of the produced fluid fromthe well. In yet another example, the method further comprises ionizingthe recycled portion of the produced fluid. In another example, themethod wherein the ionized fluid being generated comprises recycledfluid, produced fluid, and makeup fluid.

In a more specific example, a means system for increasing hydrocarbonproduction from a subsurface formation comprises: means for generatingan ionized fluid; means for transporting the ionized fluid from thesurface into at least one fracture zone of the subsurface formation,means for pressuring the ionized fluid at the at least one fracturezone; means for maintaining the pressurize at the at least one fracturezone; means for depressurizing the ionized fluid at the at least onefracture zone; wherein a portion of the ionized fluid returns to thesurface carrying suspended particles of the formation. In yet anotherexample, the means for generating ionized fluid further comprises ameans for treating water with electromagnetic fields of influence. Inanother example, the system wherein the means for generating theelectromagnetic fields of influence comprises: a pipe; and at least oneelectrical coil having an axis substantially coaxial with the pipe. In afurther example, the system wherein the electromagnetic fields ofinfluence are generated at a full wave frequency of more than eightypulses per second.

In yet another example, the system wherein the ionized fluid is composedof at least fifty percent water by volume.

In another example, the system wherein the electromagnetic fields ofintluence are generated at a full wave frequency of up to three hundredand sixty pulses per second. In a further example, the system whereinthe electromagnetic fields of influence eliminate the majority of themicro-organisms within the ionized fluid.

In another example, the system further comprises a means for addingproppant to the ionized fluid. In yet another example, the systemwherein said means for adding proppant to the ionized fluid comprises ablender.

In another example, the system wherein said means for transporting theionized fluid from the surface into a fracture zone of the subsurfaceformation comprises coiled tubing.

In yet another example, the wherein said means for pressuring theionized fluid at the fracture zone comprises at least one fracturingpump.

In a further example, the system wherein said means for maintaining thepressure at the fracture zone comprises at least one packer.

In yet another example, the system wherein said means for depressurizingthe ionized fluid at the fracture zone comprises coiled tubing. Inanother example, the system further comprises a drill mechanism attachedto the coil tubing adapted to compromise the at least one packer.

In a further example, the system further comprises a means for recyclingflowback fluid, wherein a portion of the recycled flowback fluid is usedto generate the ionized fluid. In yet another example, the systemfurther comprises a means for separating the flowback into water and atleast one other substance.

In yet another example, the system wherein the ionized fluid comprisespositively charged water. In another example, the system furthercomprises a means for recycling produced fluid, wherein a portion of therecycled produced fluid is used to generate the ionized fluid. In anexample, the system further comprises a means for separating theproduced fluid into water and at least one other substance.

In a more specific example, a method for increasing hydrocarbonproduction from a subsurface formation comprising: generating ionizedfluid, re-entering a formation; accessing at least one select locationwithin a hydrocarbon well; pumping the ionized fluid from a surfacelocation into the subsurface formation at the at least one selectedlocation in a hydrocarbon well, pressuring the ionized fluid in at leastone selected location, depressurizing the ionized fluid in at least oneselected location, wherein at least a portion of the ionized fluidreturns to the surface location containing suspended materials. In afurther example, the method further comprises eliminating the majorityof the micro-organisms within the ionized fluid. In yet another example,the method wherein the ionized fluid composition comprises at leastfifty percent water by volume.

In yet another example, the method wherein the ionized fluid comprisespositively charged water.

In a further example, the method wherein the ionized fluid is generatedby subjecting a fluid to electromagnetic fields of influence. In yetanother example, the method wherein the electromagnetic fields ofinfluence are pulsed at a full wave of more than eighty times persecond. In a further example, the method wherein the electromagneticfields of influence are pulsed at a full wave of up to three hundred andsixty times per second.

In yet another example, the method wherein the suspended particlesinclude calcium based suspended particles. In another example, themethod further comprising isolating the at least one selected locationfrom at least one portion of the hydrocarbon well.

In a further example, the method further comprises perforating in atleast one selected location.

In yet another example, the method further comprises fracturing at leastone selected location.

In another example, the method further comprises mixing the ionizedfluid with a proppant. In yet another example, the method furthercomprising isolating the at least one selected location from a secondselected location.

In a further example, the method further comprises installing at leastone packer to isolate at least one selected location from at least oneportion of the hydrocarbon well.

In an example, the method further comprises drilling out at least onepacker.

In a more specific example, a method of increasing production from asubsurface shale formation comprises: generating ionized fluid withelectromagnetic fields of influence; pumping the ionized fluid into thesubsurface shale formation; and exposing the previously perforated zoneto ionized fluid under pressure; wherein the production from thesubsurface shale increases after the ionized fluid is depressurized,wherein the previously perforated zone has been previously fractured,further comprising fracturing the previously perforated zone and,further comprising selecting a zone to expose to ionized fluid.

In a further example, the method further comprises perforating theselected zone. In another example, the method further comprisesfracturing the selected zone and isolating the selected zone. In yetanother example, the method further comprises pressurizing the selectedzone with ionized water. In yet another example, the method furthercomprises holding the pressure in the selected zone for a predeterminedperiod of time. In yet another example, the method further comprisesreleasing the pressure in the selected zone. In yet another example, themethod further comprises mixing the ionized fluid with a proppant.

In a more specific example, a device for use in a hydrocarbon wellfracture operation comprising: an electromagnetic field generator havinga first fluid input port and a first fluid output port; at least onefracturing pump having a second fluid input port connect to the firstfluid output port of the electromagnetic field generator; and a coiledtubing device having the coil tubing input connect to the second fluidoutput port, and further comprises at least one well fracture toolattached to the coil tubing. In yet another example, the device furthercomprises at least one well perforation tool attached to the coiledtubing. In yet another example, the device further comprises at leastone pipe in within the electromagnetic field generator located betweenthe first fluid input port and the first fluid output port.

In yet another example, the device further comprises at least oneelectromagnetic coil surrounding at least one pipe. In another example,the device further comprises at least one completions tool attached tothe end of coiled tubing.

In yet a further example, the device further comprises a wellhead at thesurface of the hydrocarbon well, wherein the coiled tubing interfaceswith the hydrocarbon well by way of the wellhead. In another example,the device further comprises a flowback line from the wellhead with anoutlet port. In yet another example, the device further comprises theflowback line outlet port connected to a separator, the separator havingan inlet port and at least one outlet port. In a even further example,the device further comprises at least one separator outlet portconnecting to a second inlet port on the electromagnetic fieldgenerator.

At least one embodiment of the claimed invention may include a methodfor increasing hydrocarbon production from a subsurface formation, themethod comprising, generating ionized fluid, pumping the ionized fluidfrom a surface location into at least one subsurface location in ahydrocarbon well, pressuring the ionized fluid at least one subsurfacelocation, depressurizing the ionized fluid at the perforated location,wherein at least a portion of the ionized fluid returns to the surfacelocation containing suspended materials. The embodiment may furtherinclude perforating and fracturing at least one subsurface location.Furthermore, the ionized fluid may comprise positively charged water.The ionized fluid may be generated by exposing water to electromagneticfields of influence.

The embodiment of the invention may also include the electromagneticfield of influence being pulsed at a full wave of up to three hundredand sixty times per second. Furthermore, the suspended particles mayinclude calcium based suspended particles. The embodiment furtherrecycles a portion of the flowback fluid from the well. The embodimentmay also ionize the recycled portion of the fluid recovered from thewell. Finally, re-entering the formation is a option to further increasethe production of the well.

Another embodiment of the claimed invention may include a system forincreasing hydrocarbon production from a subsurface formation comprisinga means for generating an ionized fluid, a means for transporting theionized fluid from the surface into at least one fracture zone of thesubsurface formation, a means for pressuring the ionized fluid at the atleast one fracture zone, a means for maintaining the pressurize at theat least one fracture zone, a means for depressurizing the ionized fluidat the at least one fracture zone; wherein a portion of the ionizedfluid returns to the surface carrying suspended particles of theformation. The ionized fluid may comprise at least fifty percent waterby volume. The means for generating ionized fluid may include generatingelectromagnetic fields of influence at a full wave frequency of up tothree hundred and sixty pulses per second. The electromagnetic fields ofinfluence would eliminate the majority of the micro-organisms within theionized fluid. The embodiment may include a means for adding proppant tothe ionized fluid that may include a blender. It may include a drillmechanism attached to the coil tubing adapted to compromise at least onepacker in the well. The embodiment may include a means for recyclingflowback fluid, wherein a portion of the recycled flowback fluid is usedto generate the ionized fluid. Another option could include a means forseparating the flowback into water and at least one other substance. Theembodiment may also comprise a means for separating the produced fluidinto water and at least one other substance.

Another embodiment of the invention may include increasing productionfrom a subsurface shale formation comprising generating ionized fluidwith electromagnetic fields of influence, pumping the ionized fluid intothe subsurface shale formation, exposing the previously perforated zoneto ionized fluid under pressure; wherein the production from thesubsurface shale increases after the ionized fluid is depressurized. Theperforated zone may have been previously fractured. The previouslyperforated zone may be fractured again. A zone may be selected assuitable for exposing to ionized fluid. The invention may perforate theselected zone. After perforating the selected zone, an operator mayfrack the selected zone. Afterwards, the selected zone may be isolated.Then the selected zone may be pressured with ionized water. Then thepressure within the selected zone may be held for a predetermined periodof time. The pressure in the selected zone may be released. Ionizedfluid used in the selected zone may be mixed with proppant.

Another embodiment of the invention may include a device for use in ahydrocarbon well fracture operation comprising an electromagnetic fieldgenerator having a first fluid input port and a first fluid output port,at least one fracturing pump having a second fluid input port connect tothe first fluid output port of the electromagnetic field generator, anda coiled tubing device having the coil tubing input connect to thesecond fluid output port. The device may include at least one wellfracture tool attached to the coil tubing. The device may include atleast one well perforation tool attached to the coiled tubing. Thedevice may include at least one pipe within the electromagnetic fieldgenerator located between the first fluid input port and the first fluidoutput port.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a well site showing the flow of various materialsused in various examples of the invention.

FIGS. 2A and 2B, when connected along their respective dotted lines, area side view of an example of the invention.

FIG. 2A1 is an alternative to the embodiment of FIG. 2A.

FIG. 2C is a schematic of a control system used in at least one exampleof the invention.

FIGS. 3A and 3B, when connected by the overlapping components next totheir dotted lines, are a plan view of the example of FIGS. 2A and 2B.

FIGS. 3C and 3D are an isometric and side view, respectively, of anaspect of the examples of FIGS. 2A-2B and FIGS. 3A-3B.

FIG. 4 is a side view of a further example of the invention.

FIG. 5 is a plan view of the example of FIG. 4.

FIG. 6 is a diagram of a well site showing the flow of various materialsused in various examples of the invention.

FIG. 7 is a diagram of a well site showing the flow of various materialsused in various examples of the invention.

FIG. 8 is a top view of an example of the invention.

FIG. 9 is a side view of an example of the invention.

FIG. 10A is a side view of support leg 100 of FIG. 8.

FIG. 10B depicts a top view of foot 101 of FIG. 10A.

FIG. 11 is a cross section view taken through line A of FIG. 9.

FIG. 12 is a cross section view taken along line C of FIG. 8.

FIG. 13 is a cross section view taken along line B of FIG. 8.

FIG. 14A is a top view of a component of an example of the invention.

FIG. 14B is a section view of the component of FIG. 14A.

FIG. 15 is a schematic of a control system useful in examples of theinvention.

FIG. 16 is a representational view of a system useful in examples of theinvention.

FIG. 17 is a schematic of a control system useful according to examplesof the invention.

FIG. 18 is a perspective view of examples of the invention.

FIG. 19 is a perspective view of an apparatus embodying the invention.

FIG. 20 is an exploded view of the pipe unit of the apparatus of FIG.19.

FIG. 21 is a longitudinal cross sectional view taken through the pipeunit of FIG. 19.

FIG. 22 is a simplified circuit diagram of the pipe unit of FIG. 19.

FIG. 23 is a detailed schematic diagram of the electrical circuit of thepipe unit of FIG. 19.

FIG. 24 is a diagram showing certain wave shapes produced by the pipeunit of FIG. 19 during operation.

FIG. 25 is a circuit diagram similar to FIG. 4 but showing a modifiedembodiment of the invention.

FIG. 26 is a view similar to FIG. 21 but showing a modified embodimentof the invention in which the pipe unit has only one coil surroundingthe liquid flow pipe.

FIG. 27 is a detailed circuit diagram similar to FIG. 23 but showing anelectrical circuit for use with the pipe unit of FIG. 27.

FIG. 28 is a chart specifying presently preferred values of certainparameters of the apparatus of FIGS. 19 to 24.

FIG. 29 is a diagram of a well site showing the flow of variousmaterials used in various examples of the invention, including pumpingionized water into a formation.

FIG. 30 is a diagram of a perforation zone being exposed to an ionizedfluid.

FIG. 31 is a diagram of the zeta principal and showing the positioningof fields and force.

DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

Referring now to FIG. 1, a flow diagram of the use of the invention in ahydrocarbon well having a well bore 1 with cemented casing 3 passingthrough fracture zones that are isolated by packers. Coil tubing 9 isinserted by rig 11 for fracture operations known to those of skill inthe art.

Flow back (and/or produced) water is routed to three-phasesolids/liquids/gas/hydrocarbon/water separator 10, from which anyhydrocarbon liquids and gases are produced, and water from separator 10is routed to a fracturing-water storage tank 17 which may also includewater from another source (aka “make up” water). Wet solids are passedfrom three-phase separator 10 to two-phase separator 14, which produceswater that is passed to a quench system 32 and slurry that are passed tokiln 24. Slag is passed from kiln 24 through quench system 32 to crusher40 and then to mill 46. Milled material is separated into a specifiedsize at screen 50 that is sent to a proppant storage silo 26, which mayalso include proppant from another source (e.g., a supplier of sand).Water is provided to biocide/coalescer unit 13. Proppant provided toblender 15 from silo 26, water is supplied to blender 15 frombiocide/coalescer unit 13; the blended water and proppant are thenprovided to fracturing pumps 19, which pumps the blend into the wellwhere it fractures the oil shale layer 21. Other additives may beprovided to the blender 15, as desired. Also, proppant may be added tothe water before the biocide/coalescer unit 13 in alternative examples.

Examples of the invention create a range of proppants of specific sizesfrom a slurry extracted from a hydraulically-fractured hydrocarbon well.

In FIGS. 2A and 2C and in FIGS. 3A-3D, a more specific example is seen.In that example, a slurry is extracted from gravity-precipitated slurrythat accumulates at the bottom of a conventional three-phase separationtank 10 (which is of a common design known to those of skill in theart). In the specific example of FIG. 2A, as will occur to those ofskill in the art, a water/liquid hydrocarbon interface level facilitatesthe separation and recovery of any liquid hydrocarbon product from theflow back or produced water stream (which is under pressure as it entersseparator 10) by means of an internally or externally mounted waterlevel indicator (not shown). That indicator sends a water levelmeasurement signal to a pre-programmed, low level/high level water flowcontrol data integrator (not shown). When the water level in theseparator 10 reaches the high level set point, the data integratoractuates a control valve (not shown) that controls flow through thewater feed pipe 10 a (labeled “Inlet Water”) to reduce the amount ofwater going into the three phase separator, and the rate of flowcontinues to decrease until a point is reached where the incoming amountof water equalizes and balances out the volume of water being withdrawnfrom the three phase separator. Conversely, if the water level in thethree phase separator 10 falls below the low level set point, the dataintegrator actuates and further opens up the control valve in inlet pipe10 a in order to increase the amount or rate of water flow that issufficient to stabilize the interface level. If this additional amountof water is not sufficient to stabilize the water level at the interfacelevel, the integrator actuates a pump (not shown) and opens up anothercontrol valve (not shown) which is located in a discharge pipe (notshown) in water storage tank 17 (FIG. 1). That discharge pipe isconnected to the inlet pipe 10 a; thus water from fracturing waterstorage tank 17 continues to flow into the three phase separatortogether with the flow back or produced water until the water level inthe separator 10 reaches the proper interface level. Then, the make-upwater control valve closes and the make-up water pump is shut off. Thiscontrol sequence is necessary in order to achieve steady state andcontinuous operational stability in the separation and recovery of anyliquid hydrocarbon product that is carried into the three phaseseparator by the flow back or produced water feed stream.

A weir and baffle configuration (commonly known in gas/oil separationunits) facilitates the separation and recovery of the liquid hydrocarbonproduct, if any, by using the interface level as the maximum height ofthe water in the separator and allowing the lighter liquid hydrocarbonsto float on top of the water layer and then be withdrawn as liquidhydrocarbon product after it flows over the liquid hydrocarbon productweir and is withdrawn at the hydrocarbon liquid product outlet flangeconnection. A horizontal baffle under the weir limits the amount ofpotential water carry over that might be comingled with the liquidhydrocarbon product stream. As the flow back or produced water streamenters the three phase separator 10 the depressurization releases thelighter hydrocarbon gases and their release assists in the flotation ofthe liquid hydrocarbon products as well as the release of the gaseoushydrocarbon products through outlet 10 c. Water flows out of separator10 through pipe 10 b to a surge tank (not shown) and is then pumped backto water tank 17 (FIG. 1).

From separator 10, a motor-driven positive displacement diaphragm-typesludge pump 12 moves the slurry upwards to the inlet opening of atwo-phase water/solids separation tank 14 resulting in a solid stream 16and a liquid stream 18 that is pumped by pump 19 to a quench (labeled“Q”). From the bottom of the two-phase water/solids separation tank 14,a bucket-elevator conveyor 20 transports the precipitated slurrymaterials from the lower part of the water/solids separation tank 14upwards from the water level and discharges them into the feed-hopper 22(FIG. 2B). The discharge is seen in FIG. 2A as going over a dashed line,which connects with the dashed line to the left of FIG. 2B where slurryis seen accumulating in feed-hopper 22 of a slagging, rotary-kiln 24,leaving the slurry water to remain in the water/solids separation tank14 and the elevator 20. As a result, all separation is carried out atatmospheric pressure rather than in pressurized-vessels (as is currentpractice).

In the feed-hopper 22, the slurry materials from the water/slurryseparation tank are mixed with specification proppant from silo 26 (FIG.1), as well as under-sized and over-sized solid materials that come froma final screening unit 50 (described below).

As the fusion process for the proppant material proceeds, inorganicproppant materials are fused into a uniform mass and volatile organicmaterials that may have been present in the feed stream from thewater/solids separation tank 14 are burned and vaporized prior to thegases being eventually discharged into an exhaust vent 30.

The proppant material exiting from the rotary kiln 24 is quenched with astream of water to reduce the temperature of the material, as it emergesfrom the outlet of the kiln 24. In some examples, discharged materialflows onto a perforated, motor-driven stainless-steel conveyor belt 35and the water cascades, through spray nozzles 34 on to the moving belt35 thereby solidifying and cooling the proppant material. The water usedfor quenching the proppant material comes from the water/solidsseparation tank 14 (see FIG. 2A) using, e.g., a motor-driven centrifugalpump 19 to push the water to the quench nozzles 34 of FIG. 3B. An excesswater collection pan 36 is positioned under the conveyor belt 35 tocollect and recover any excess quench water and convey it back to thewater/solids separation tank 14 by a motor-driven centrifugal pump 21and a pipeline shown flowing to return “R” of FIG. 2A.

Quenching the hot proppant material, as it is discharged from the kiln24, causes a multitude of random, differential-temperature fractures orcracks due to the uneven contraction of the proppant material and thehigh internal stresses caused by rapid quenching. The different sizedpieces of proppant material are discharged directly into the materialcrusher 40.

Crushing or breaking up the large irregular pieces of proppant materialand reducing their size is accomplished, in some examples, by amotor-driven, vertical-shaft, gyratory, eccentric cone or jaw crusher,known to those of skill in the art. The degree of the size reduction isadjusted by changing the spacing or crusher gap, thus allowing a rangeof different material sizes to be produced, as is known to those ofskill in the art.

Sizing of the proppant material is accomplished by the grinding ormilling of the crushed proppant material after the proppant material isdischarged at the bottom of the crusher. In the illustrated example, thematerial is conveyed upwards to ball mill 46 by a bucket-elevatorconveyor 44. In at least one alternative example, a rod mill is used.The mill 46 is adjusted to grind the proppant material to differentspecific size ranges by changing rotation, the size and spacing of therods or balls in the mill 46 (or its rotation).

The milled proppant material flows by gravity down through the grindingzone of the mill and is discharged onto vibrating screen 50 where themesh openings are selectively sized to a specific sieve value. Forexample, for soft mineral shale the mesh openings are in the 590 micronrange or a #30 sieve. For hard mineral shale (for example) the meshopenings would be in the 150 micron range or a #100 sieve. Proppantmaterial of the proper size flows downward by gravity through aselectively sized screen exiting at “A.” Proppant material that is toolarge to pass through the slanted, vibrating screen 53 exits onto belt51 a (seen better in FIG. 3B), and the rest drops to screen 55. Proppantmaterial between the sizes of screens 53 and 55 exit as correctly sizedproppant at “A” and is transported to silo 26 (FIG. 1). Under-sizedproppant drops onto belt 51 a which conveys the under-sized andover-sized proppant to belt 51 b, which then carries the proppant backto kiln 24, through elevator 25. FIGS. 3A and 3B illustrate a top viewof an example of the invention in which the components are mounted on atrailer or skid mounted that are assembled at a well site with biocideand other components (e.g., FIGS. 4 and 5). Such trailers or skids areleveled in some examples by leveling jacks 81.

As seen in FIGS. 3C and 3D, elevator 25 deposits material into the topof feed hopper 22 and elevator 23 deposits material from the silo intofeed hopper 22 from a lower level through an opening in feed hopper 22.

The properly-sized proppant materials flow is fed, by gravity, into aspecification proppant container (not shown) for transfer to thespecification proppant storage silo 26 (FIG. 1) which may also containspecification proppant from another source.

Referring now to FIG. 2B, it is desirable to control the viscosity ofthe proppant feed mixture, to attain stability of sustaining an optimumfusion temperature (in some examples, approximately 2200 degreesFahrenheit). As the proppant feed mixture temperature is rising, due tothe heat in kiln 24, the process of fusing the various inorganicmaterials into a uniformly viscous mass is achieved when the temperaturein the proppant mixture reaches the fusion temperature of silicondioxide or sand. The viscosity of the proppant material is a function ofthe temperature of the material itself. Such control is accomplished invarious ways.

In at least one example, the temperature of the fused material ismeasured, by any means know to those of skill in the art, for example,an optical pyrometric sensor in quench system 32, as it exits from thekiln. If the temperature is above the fusion point of the material, itwill be too liquid, and the fuel to the kiln is reduced. At the sametime, more specification proppant may be added to the feed hopper 22.This affects the temperature because the material coming from the slurryis not uniform and is not dry; adding proppant from the silo evens outthe variability.

Referring now to FIG. 2C, a schematic is seen in which sensor 67 signalsintegrator 69 with the temperature of the output of the kiln 24.Integrator 69 then controls variable-speed motor 90 (FIG. 3A) thatoperates elevator 23 (see also FIG. 3B) that carries proppant from thebottom of proppant silo 26 and discharges it into the slagging rotarykiln feed-hopper 22. The different material streams are comingled in thefeed-hopper 22 before they enter the revolving drum of the kiln 24. Theproportion or amount of specification proppant that is needed to beadded to the material stream from the water/solids tank 14 is adjusted,depending upon the changes in the composition of the materials comingfrom the water/solids separation tank 14. This increases uniformity ofthe proppant material feed mixture that kiln 24 uses in the fusionprocess. In at least one example, if the temperature is too high, thefuel to the burner is reduced; if that does not correct it, the amountof proppant to the kiln will be increased. Likewise, if the temperatureis too low, the fuel is increased to the burner; and, if that does notwork, the amount of proppant is decreased. Alternative arrangements willoccur to those of skill in the art.

Referring back to FIG. 2C, integrator 69 also controls valve 63 toincrease or decrease the supply of fuel 61 for kiln burner 65.

Referring again to FIG. 1, one example of the invention is seen in whichseparator 10 is seen feeding the slurry to separator 14, and water fromseparator 10 is the joined with new “make-up” (in tank 17) water to beused in injection in a new fracturing job. The combined flows aretreated by an electromagnetic biocide/coalescer 13 of the type describedin U.S. Pat. No. 6,063,267, incorporated herein by reference for allpurposes (commercially available as a Dolphin model 2000), which is set,in at least one example, to impart an electro-magnetic pulse having thefollowing characteristics: selectable, variable, and tuneablefrequencies in a range between about 10-80 kHz. Such a pulse issufficient to kill biological organisms and to cause a positive chargeto be applied to the water, making the dissolved solids capable of beingprecipitated or coalesced in the well.

FIGS. 4 and 5 are side and top views, respectively, of an exampletrailer-mounted or skid-mounted system that includes a set ofbiocide/coalescers 70 a-70 l, organized to receive fracturing tank waterin the type of flow rate used in common shale-fracture operations. Suchunits are run from an electrical control panel 72, that is connected toan overhead power and control distribution rack 73 that connects tooverhead power feed components 71 a-71 l. Power is supplied by an engine75 that turns an electrical generator 77 that is connected to power feed79 for supplying power in a manner known to those of skill in the art.

Referring now to FIG. 2A1, an alternative to the embodiment of FIG. 2Aas seen in which the water level of two-phase separator 14 is at thesame as the level and three-phase separator 10. In such an embodiment,there is fluid communication through a diaphragm pump 12 and tanks areat atmospheric pressure such that the liquid gas interface is at thesame level.

Referring now to FIG. 6, according to another example of the invention,a system is provided for treating hydrocarbon well fracture water from ahydrocarbon well, system comprising a means for separating solids fromfracture water comprising a three-phase, four material separator 10,wherein a flow of water with suspended solids results that is passed toa fracturing water storage tank 17. From there so-called “make-up water”may be added to fracture water storage tank 17 and the flow of water ispassed through a means for separating the flow of water into a pluralityof flows of water (described in more detail below); to a means forgenerating positive charge in the plurality of flows of water (forexample, a set of biocide coalescers or units as described above),wherein a plurality of flows of positively-charged water results. Ameans for comingling plurality of flows of positively-charged water moreevenly distributes the positive charge in the water before it is passedto blender 15 for use in subsequent well fracturing operations.

FIG. 7 illustrates an example in which the means for separating furthercomprises a second stage, two-phase separator 14, the two-phaseseparator comprising an input for receiving water flow from thethree-phase gas oil separator. The water flow from the three-phaseseparator is taken from the midsection of the separator, while mostsolids dropped out at the bottom, as described above. However, the waterfrom the three-phase separator includes suspended solids that can damagea biocide coalesce or unit. Accordingly, in one example embodiment, thewater flow from the three-phase separator 10 is passed to the input of atwo-phase separator 14, which also includes an output for the flow ofwater with suspended smaller suspended solids. Two-phase separator 14also drops solids out of its lower section in the form of a slurry. Theslurry from three-phase separator 10 and two-phase separator 14 arefurther processed (for example as described above) or disposed of insome other manner.

Referring now to FIGS. 8 and 9, an example of a three-phase,four-material separator 90, according to some embodiments of theinvention and place of three-phase separator 10, as seen. Separator 90and includes an input 92, a slurry output 94, a liquid hydrocarbonoutput 98 and a gas output 80. As also seen in FIG. 10A, separator 90 issupported by legs 100 (which includes a foot 101, as seen in FIG. 10B)welded to the side of separator 90.

Referring again to FIG. 9, as well as FIG. 11 (which is across sectiontaken through line A of FIG. 9) and FIG. 13 (which is a cross-sectionaltaken along line B of FIG. 8), a baffle 111 allows water having somesuspended solids to exit separator 90 while larger solids exit as theslurry at the bottom exit 94. FIG. 12 illustrates a cross-section ofinput 92 (taken along line C of FIG. 8) where input pipe 92 is supportedby support 120 connected to the bottom of separator 90 and holding inputpipe 92 and a saddle.

In a further example, there is also provided: means for monitoring anoil/water interface level; and means for controlling the oil/waterinterface level in the first and second separator. In one such example,the means for monitoring comprises an oil/water interface levelindicator and control valve sensor (for example, a cascade controlsystem).

As illustrated in FIG. 18, in some examples, the means for separatingthe flow of water into a plurality of flows of water comprises amanifold 181 having an input port valve 183 to receive the flow of waterwith suspended solids from a means for separating and a plurality ofoutput ports attached to biocide coalescer units 184, each output porthaving a cross-sectional area that is smaller than the cross-sectionalarea of the input of the manifold. In some examples, the sum of thecross-sectional areas of the output ports is greater than thecross-sectional area of the input ports, whereby the flow rate exitingthe manifold is less than the flow rate entering the manifold. In atleast one example, the manifold 181 comprises a 1:12 manifold (forexample, having cross-sectional diameters of 4 inches in the outputports and a larger cross sectional diameter in the input ports). In analternative example, the means for separating the flow of water into aplurality of flows of water comprises a water truck as is known in theart (not shown) having a plurality of compartments, each compartmentbeing positioned to receive a portion of the flow of water. Inoperation, water passes through valve 183 into manifold 181 and the flowis slowed as it is separated into parallel flows through theparallel-connected biocide coalescer units 184 to increase residencetime for imparting electromagnetic flux in order to maximize thepositive charges the electromagnetic flux imparts to the water. Theoutput of the units 184 is comingled in manifold 186, who's output iscontrolled by valve 188. The entire assembly of the manifolds andbiocide coalescer units is, in some examples, mounted on frame 184 whichmay be lifted by harness 186 onto a pad at a well site or onto the bedof a truck for transportation.

In a further example, the means for generating positive charge comprisesmeans for treating each of the plurality of flows of water withelectromagnetic flux. At least one such example is seen in FIGS. 19-28,where the means for treating each of the plurality of flows of waterwith electromagnetic flux comprises: a pipe and at least one electricalcoil having an axis substantially coaxial with the pipe. In some suchexamples, the pipe consists essentially of non-conducting material. Insome such examples, the pipe consists essentially of stainless steel. Ina variety of examples, there is also provided a ringing currentswitching circuit connected to the coil. In some such examples, theringing current switching circuit operates in a full-wave mode at afrequency between about 10 kHz to about 80 kHz.

Specifically, still referring to FIGS. 19-28, turning first to FIG. 19,an apparatus embodying the invention is indicated generally at 910 andcomprises basically a pipe unit 912 and an alternating currentelectrical power supply 914. The pipe unit 912 includes a pipe 916through which liquid to be treated passes with the direction of flow ofliquid being indicated by the arrows A. The pipe 916 may be made ofvarious materials, but as the treatment of the liquid effected by thepipe unit 912 involves the passage of electromagnetic flux through thewalls of the pipe and into the liquid passing through the pipe, the pipeis preferably made of a non-electrical conducting material to avoiddiminution of the amount of flux reaching the liquid due to some of theflux being consumed in setting up eddy currents in the pipe material.Other parts of the pipe unit 912 are contained in or mounted on agenerally cylindrical housing 918 surrounding the pipe 916.

The pipe unit 912 is preferably, and as hereinafter described, onedesigned for operation by a relatively low voltage power source, forexample, a power source having a voltage of 911 V(rms) to 37 V(rms) anda frequency of 60 Hz and, therefore, the illustrated power supply 914 isa voltage step down transformer having a primary side connected to aninput cord 920 adapted by a plug 922 for connection to a standard mains,such as one supplying electric power at 120 V 60 Hz or 240 V 60 Hz, andhaving an output cord 924 connected to the secondary side of thetransformer and supplying the lower voltage power to the pipe unit 912.The pipe unit 912 may be designed for use with pipes 916 of differentdiameter and the particular output voltage provided by the power source914 is one selected to best suit the diameter of the pipe and the sizeand design of the related components of the pipe unit.

The pipe unit 912, in addition to the housing 918 and pipe 916, consistsessentially of an electrical coil means surrounding the pipe and aswitching circuit for controlling the flow of current through the coilmeans in such a way as to produce successive periods of ringing currentthrough the coil means and resultant successive ringing periods ofelectromagnetic flux passing through the liquid in the pipe 916. Thenumber, design and arrangement of the coils making up the coil means mayvary, and by way of example in FIGS. 20 and 21 the coil means is shownto consist of four coils, L₁, L₂-outer, L₂-inner and L₃ arranged in afashion similar to that of U.S. Pat. No. 5,702,600, incorporated hereinby reference for all purposes. The coils, as shown in FIGS. 20 and 21,are associated with three different longitudinal sections 926, 928 and930 of the pipe 916. That is, the coil L₁ is wound onto and along abobbin 932 in turn extending along the pipe section 926, the coil L₃ iswound on and along a bobbin 934 itself extending along the pipe section930, and the two coils L₂-inner and L₂-outer are wound on a bobbin 936itself extending along the pipe section 928, with the coil L₂-outerbeing wound on top of the coil L₂-inner. The winding of the two coilsL₂-inner and L₂-outer on top of one another, or otherwise in closeassociation with one another, produces a winding capacitance betweenthose two coils which forms all or part of the capacitance of a seriesresonant circuit as hereinafter described.

Referring to FIG. 20, the housing 918 of the pipe unit 912 is made up ofa cylindrical shell 938 and two annular end pieces 940 and 942. Thecomponents making up the switching circuit are carried by the end piece940 with at least some of them being mounted on a heat sink 944 fastenedto the end piece 940 by screws 946. In the assembly of the pipe unit912, the end piece 940 is first slid onto the pipe 916, from the rightend of the pipe as seen in FIG. 20, to a position spaced some distancefrom the right end of the pipe, and is then fastened to the pipe by setscrews 948. The three coil bobbins 932, 936 and 934, with their coils,are then moved in succession onto the pipe 916 from the left end of thepipe until they abut one another and the end piece 940, with adhesiveapplied between the bobbins and the pipe to adhesively bond the bobbinsto the pipe. An annular collar 950 is then slid onto the pipe from theleft end of the pipe into abutting relationship with the coil L₃ and isfastened to the pipe by set screws 960, 960. The shell 938 is then slidover the pipe and fastened at its right end to the end piece 940 byscrews 962, 962. Finally, the end piece 942 is slid over the pipe 916,from the left end of the pipe, and then fastened to the shell 938 byscrews 964 and to the pipe by set screws 966.

The basic wiring diagram for the pipe unit 912 is shown in FIG. 22. Theinput terminals connected to the power source 914 are indicated at 968and 970. A connecting means including the illustrated conductorsconnects these input terminals 968 and 970 to the coils and to theswitching circuit 972 in the manner shown with the connecting meansincluding a thermal overload switch 974. The arrow B indicates theclockwise direction of coil winding, and in keeping with this referencethe coil L₃ and the coil L₂-outer are wound around the pipe 916 in theclockwise direction and the coils L₁ and L₂-inner are wound around thepipe in the counterclockwise direction. Taking these winding directionsand the illustrated electrical connections into account, it will beunderstood that when a current i_(c) flows through the coils in thedirection indicated by the arrows C, the directions of the magneticfluxes passing through the centers of each of the coils, and thereforethrough the liquid in the pipe, are as shown by the arrows E, F, G and Hin FIG. 22. That is, the fluxes passing through the centers of the coilsL₁, L₂-inner and L₃ move in one direction longitudinally of the pipe andthe flux passing through the center of the coil L₂-outer moves in theopposite direction. Depending on the design of the switching circuit972, it may be necessary or desirable to provide a local ground for theswitch circuit 972 and when this is the case, the switching circuit maybe connected with the input terminals 968 and 970 through an isolationtransformer 976, as shown in FIG. 22.

FIG. 23 is a wiring diagram showing in greater detail the connectingmeans and switching circuit 972 of FIG. 22. Referring to FIG. 23, theswitching circuit 972 includes a 12 V power supply subcircuit 976, acomparator subcircuit 978, a timer subcircuit 980, a switch 982 and anindicator subcircuit 984.

The components D2, R5, C5, R6 and Z1 comprise the 12 V DC power supplysubcircuit 976 which powers the other components of the trigger circuit.Resistors R1 and R2 and the operational amplifier U1 form the comparatorsubcircuit 978. The resistors R1 and R2 form a voltage divider thatsends a signal proportional to the applied AC voltage to the operationalamplifier U1. The capacitor C1 serves to filter out any “noise” voltagethat might be present in the AC input voltage to prevent the amplifierU1 from dithering. The amplifier U1 is connected to produce a “low”(zero) output voltage on the line 986 whenever the applied AC voltage ispositive and to produce a “high” (+12 V) output when the AC voltage isnegative.

When the AC supply voltage crosses zero and starts to become positive,the amplifier U1 switches to a low output. This triggers the 555 timerchip U2 to produce a high output on its pin 93. The capacitor C2 and R3act as a high-pass filter to make the trigger pulse momentary ratherthan steady. The voltage at pin 92 of U2 is held low for about one-halfmillisecond. This momentary low trigger voltage causes U2 to hold asustained high (+12 V) on pin 93.

The switch 982 may take various different forms and may be a sub-circuitconsisting of a number of individual components, and in all events it isa three-terminal or triode switch having first, second and thirdterminals 988, 990 and 992, respectively, with the third terminal 992being a gate terminal and with the switch being such that by theapplication of electrical signals to the gate terminal 992 the switchcan be switched between an ON condition at which the first and secondterminals are closed relative to one another and an OFF condition atwhich the first and second terminals are open relative to one another.In the preferred and illustrated case of FIG. 23, the switch 982 is asingle MOSFET (Q1). The MOSFET (Q1) conducts, that is sets the terminals988 and 990 to a closed condition relative to one another, as soon asthe voltage applied to the gate terminal 992 becomes positive as aresult of the input AC voltage appearing across the input terminals 968and 970 becoming positive. This in turn allows current to build up inthe coils L₁, L₂-inner, L₂-outer, and L₃. When the time constant formedby the product of the resistor R4 and the capacitor C3 has elapsed, the555 chip U2 reverts to a low output at pin 93 turning the MOSFET (Q1) toits OFF condition. When this turning off of (Q1) occurs, any currentstill flowing in the coils is diverted to the capacitance which appearsacross the terminals 988 and 990 of (Q1). As shown in FIG. 23, thiscapacitance is made up of the wiring capacitance C_(c) arisingprincipally from the close association of the two coils L₂-inner andL₂-outer. This winding capacitance may of itself be sufficient for thepurpose of creating a useful series resonant circuit with the coils, butif additional capacitance is needed, it can be supplied by a separatefurther tuning capacitor (C_(t)).

When the switch (Q1) turns to the OFF or open condition, any currentstill flowing in the coils is diverted to the capacitance (C_(c) and/orC₁) and this capacitance in conjunction with the coils and with thepower source form a series resonant circuit causing the current throughthe coils to take on a ringing wave form and to thereby produce aringing electromagnetic flux through the liquid in the pipe 916. Byadjusting the variable resistor R4, the timing of the opening of theswitch (Q1) can be adjusted to occur earlier or later in each operativehalf cycle of the AC input voltage. Preferably, the circuit is adjustedby starting with R4 at its maximum value of resistance and then slowlyadjusting it toward lower resistance until the LED indicator 994 of theindicator subcircuit 984 illuminates. This occurs when the peak voltagedeveloped across the capacitance (C_(c) and/or C_(t)) exceeds 150 V atwhich voltage the two Zener diodes Z2 can conduct. The Zener diodescharge capacitor 962 and the resulting voltage turns on the LED 994.When this indicator LED lights, the adjustment of the resistor R4 isthen turned in the opposite direction until the LED just extinguishes,and this accordingly sets the switch (Q1) to generate a 150 V ringingsignal.

FIG. 24 illustrates the function of the circuit of FIG. 23 by way ofwave forms which occur during the operation of the circuit. Referring tothis Figure, the wave form 996 is that of the AC supply voltage appliedacross the input terminals 968 and 970, the voltage being an alternatingone having a first set of half cycles 998 of positive voltagealternating with a second set of half cycles 900 of negative voltage.The circuit of FIG. 23 is one which operates in a half wave mode withperiods of ringing current being produced in the coils of the pipe unitonly in response to each of the positive half cycles 998. The wave form902 represents the open and closed durations of the switch (Q1), andfrom this it will be noted that during each positive half cycle 998 ofthe supply voltage the switch (Q1) is closed during an initial portionof the half cycle and is opened at a time well in advance of the end ofthat half cycle (with the exact timing of this occurrence beingadjustable by the adjustable resistor R4).

The opening and closing of the switch (Q1) produces the current waveform indicated at 904 in FIG. 24 which for each positive half cycle ofthe supply voltage is such that the current through the coils increasesfrom zero during the initial portion of the half cycle, during which theswitch (Q1) is closed, and then upon the opening of the switch (Q1) thecurrent rings for a given period of time. The voltage appearing acrossthe coils of the pipe unit is such as shown by the wave form 906 of FIG.24, with the voltage upon the opening of the switch (Q1) taking on aringing shape having a maximum voltage many times greater than thevoltage provided by the power supply 914.

The frequency of the ringing currents produced in the coils and of theringing voltages produced across the coils can be varied by varying thecapacitance (C_(c) and/or C_(t)) appearing across the switch (Q1) and ispreferably set to be a frequency within the range of 10 kHz to 80 kHz.

Parameters of the apparatus of FIGS. 19-24, including nominal pipe size,arrangement of coils in terms of number of turns, gage and length,tuning capacitor capacitance and associated nominal power supply voltageare given in the form of a chart in FIG. 28.

As mentioned above, the switching circuit illustrated and described inconnection with FIGS. 22, 23 and 24 is one which is operable to produceone period of ringing current and ringing voltage for each alternatehalf cycle of the applied supply voltage. However, if wanted, theswitching circuit can also be designed to operate in a full wave modewherein a period of ringing current and of ringing voltage is producedfor each half cycle of the supply voltage. As shown in FIG. 25, this canbe accomplished by modifying the circuit of FIG. 22 to add a secondswitching circuit 908 which is identical to the first switching circuit972 except for facing current wise and voltage wise in the oppositedirection to the first circuit 972. That is, in FIG. 25 the firstcircuit 972 operates as described above during each positive half cycleof the applied voltage and the second circuit 908 operates in the sameway during the negative half cycles of the applied voltage, and as aresult, the number of periods of current and voltage ringing over agiven period of time is doubled in comparison to the number of periodsproduced in the same period of time by the circuit of FIG. 22.

Also, as mentioned above, the number of coils used in the pipe unit 912may be varied and if wanted, the pipe unit 912 may be made with only onecoil without departing from the invention. FIGS. 26 and 27 relate tosuch a construction with FIG. 26 showing the pipe unit to have a singlecoil 910 wound on a bobbin 912 and surrounding the pipe 916. Theswitching circuit used with the single coil pipe unit of FIG. 26 isillustrated in FIG. 27 and is generally similar to that of FIG. 23except, that because of the single coil 910 producing no significantwiring capacitance, it is necessary to provide the tuning capacitor(C_(t)) across the first and second terminals 988 and 990 of the switch(Q1). Further, since the coil means is made up of the single coil 910and located entirely on one side of the switch (Q1), it is unnecessaryto provide the isolation transformer 976 of FIG. 23 to establish a localground for the components of the switching circuit.

In still a further example, seen in FIG. 18 means for co-minglingcomprises a manifold 186 having input ports for a plurality of flows ofpositively-charged water from multiple means for generating positivecharge 184 and an output port connected to valve 188 directing an outputflow of water having positive charges therein to a blender for use inwell fracturing operations. In a variety of examples, the majority ofthe suspended solids are less than about 100 microns. In some suchexamples substantially all the suspended solids are less than about 100microns. In a more limited set of examples, the majority of thesuspended solids are less than about 10 microns. In an even more limitedset of examples, substantially all the suspended solids are less thanabout 10 microns.

Referring now to FIGS. 16 and 17, a system is shown for controlling ofwater/liquid hydrocarbon interface in the three-phase separator, wherein the system comprises: means for establishing a water/liquidhydrocarbon interface in a three-phase separator; means for measuringthe water/liquid hydrocarbon interface in the three-phase separator,wherein a water/liquid hydrocarbon interface measurement signal results;means for comparing the water/liquid hydrocarbon interface measurementsignal to a set point, wherein a comparison signal results; means forreducing the flow into the three-phase separator of hydrocarbon wellfracture water when the comparison signal indicates the water/liquidhydrocarbon interface is above the set point and for increasing flowinto the three-phase separator when the comparison signal indicates thewater/liquid hydrocarbon interface is below the set point, wherein theincreasing flow comprises hydrocarbon well fracture water from andmake-up water.

In at least one example, best seen in FIGS. 14A and 14B, the means forestablishing a water/liquid hydrocarbon interface comprises a diaphragmwier 140, and, ideally, the oil-water interface is established at thewier-bottom 140 b. Controlled by flow meters and control valves seen inFIGS. 15 and 16.

Referring now to FIG. 17, a more detailed example is seen of theinterface level control of a three phase, four material separator isprovided. As seen in the Figure, inlet flow of flow-back water to theseparator is measured by turbine meter (FE-101)/transmitter (FT-101) andcontrolled by flow control valve (FV-101) via flow controller (FIC-101).Make-up water inlet flow is measured by orifice plate (FE-103)/dPtransmitter (FT-103) and controlled by flow control valve (FV-103) viaflow controller (FIC-103). Water outflow is measured by orifice plate(FE-102)/dP transmitter (FT-102) and controlled by flow control valve(FV-102) via flow controller (FIC-102). The oil and water interfacelevel in the separator is measured by a magnetic level gauge (LG-100)and also by continuous capacitance level transmitter (LT-100). Bothlevel devices are mounted on an external level bridle made up of 2 inchdiameter pipe. The bridle comprises manual valves (HV-1, HV-2, HV-3,HV-4, HV-5, HV-6, HV-9, and HV-10) for maintenance on the bridle andattached instrumentation as will occur to those of skill in the art.HV-1 and HV-2 are used to isolate the bridle from the process. HV-3 andHV-4 are used to drain and vent the bridle respectively. HV-5 and HV-6are used to isolate the level gauge from the process. HV-9 and HV-10 areused to isolate the level transmitter chamber from the process. Eachinstrument on the bridle is equipped with valves for maintenance. HV-7and HV-8 are a part of the level gauge and are used to drain and ventthe level gauge respectively. HV-11 is a part of the level transmitterchamber and is used to drain the chamber.

The water/liquid hydrocarbon interface (aka “oil/water interface”) levelin the separator is maintained by level controller (LIC-100) withcascade control to flow-back inlet flow controller (FIC-101), make-upwater inlet flow controller (FIC-103) and water outflow controller(FIC-102). Cascade control is accomplished by the level controllersending a remote set point (RSP) to the associated flow controllers andresetting their set points to maintain interface level.

All controllers are set for steady state condition to maintain normalliquid level (NLL=50%). Set points for individual controllers aredetermined by desired capacity and separator sizing.

In one operational example, as the interface level increases, the levelcontroller resets the water outflow controller to throttle open whileresetting the flow-back inlet flow controller to throttle back tomaintain normal liquid level. An high liquid level (HLL=80%) alarm istriggered from an interface level transmitter analog signal to anoperator, allowing the operator should take appropriate actions toregain control of the interface level or operating conditions.

As interface level decreases, the level controller resets the wateroutflow controller to throttle back while the resetting flow-back inletflow controller to throttle open to maintain normal liquid level. Ifinterface level decreases to a low liquid level (LLL=10%), the systemplaces the make-up water flow controller on cascade control from theinterface level controller by software switch LX-100.

Referring now to FIG. 29, a flow diagram of the use of an example of theinvention in a hydrocarbon well having a well bore 301 with wellborecemented casing 303 passing through fracture zones 340 that are isolatedby packers 341. Coil tubing 309 is inserted by rig 311 for fractureoperations known to those of skill in the art. Perforations 356 are madeinto the shale layer 321. As part of the perforation and pluggingoperation, packers 341 are placed in the borehole to isolate thedifferent fracture zones 340. The coil tubing 309 is inserted into thetargeted areas where fracturing is desired. A fluid, in this caselargely comprising of water, is pumped through an ion generator 313. Theion generator 313 uses electromagnetic fields of influence describedherein to generate ionization within the fluid. This now ionized fluid353 is pumped via fracturing pumps 319 into the fracture zones 340.

The ionized fluid 353 is pumped into the fissures 351 as depicted inFIG. 30. The ionized fluid 353 is pressurized sufficiently to grow andenlarge the fissure 351. The ionized fluid 353 is held at pressure for apredetermined amount of time. While at pressure, the ionized fluid 353interacts with the shale layer 321, in this example layered calcite 350,to create layers of aragonite crystals 352. The fracture zone 340 isdepressurized by coiled tubing 309 in this example. The fracture processcan vary depending on the service provider and the environment of thewell. For instance, in an open hole application, a frack point systemmay be used instead of a perforate and plug system. These variations onthe fracturing processes possible in a shale formation are well known toa person of ordinary skill in the art.

During the fracturing operation, fissures 351 within the shale layer 321are created and/or enlarged. The fissures may be created byperforations, high pressure abrasion techniques, or other methods knownin the art. These fissures 351, located in the fracture zone 340, exposelayered calcite crystals 350 to the wellbore 301. When the layeredcalcite 350 orthorhombic crystal is exposed to the ionized fluid 353,the crystalline insoluble particle structure of the layered calcite 350is transformed into a layered aragonite 352, having an orthorhombiccrystal line shape. This layered aragonite 352 is in suspension.

Ionized fluid 353 has the ability to avoid scaling encrustation, becausethe particles that cause the scaling are now in suspension instead ofsolution. By exposing the layered calcite 350 to ionized fluid 353, theparticles form faster than if no ions are present. This phenomenondecreases the size of the particles, preventing them from being largeenough to cause encrustations or scaling on the exposed surface of thefissures 351.

Ionized fluid 353, in this example ionized water, also eliminates theproblem of non-biological suspended particle growth because of itseffect on avoiding surface nucleated precipitation. In addition, theeffect of ionized water inhibits corrosion. Paracolloidal particles ofcalcium carbonate (CaCO₃) are charged by ionic adsorption, causing themto decrease in size such that they are insoluble and remain insuspension. They are transformed into suspended crystalline germs oforthorhombic aragonite of calcium carbonate and remain in suspension.

When the ionized fluid 353 in the fissures 351 at the target fracturingzones 340 is depressurized with coiled tubing, in this example, thecalcium carbonate suspended particles 352, in this example, aragonitecrystals, are removed from the fissures 351 with the flow back water orremoved by the produced fluids from the formation.

Ionized water has the ability to avoid the buildup of non-biologicalmatter at the fissures 351. The water is ionized via electromagneticfields of influence, using for example a Dolphin unit as the iongenerator 313, utilizing periodic low frequency waveform, therebycausing the electroporation of the signal and amplification of theringing signal by resonance. The low power, high frequency, EM waveseventually kill or rupture the membranes of the micro-organisms withinthe fluid being ionized. Encapsulation of organic debris also occurs asa result of these reactions. The micro-organisms cannot reproducethemselves to form biofilm which clog the fissures 351. The ionizedfluid in this example, which is largely comprise of water, is generatedby an ion generator 313 by exposing a fluid to electromagnetic fields ofinfluence at a full wave in the frequency range of eighty kilohertz (80kHz) to three hundred and sixty kilohertz (360 kHz). In otherembodiments the frequency may simply be higher than eighty kilohertz (80kHz). In this example, a frequency of three hundred and sixty kilohertz(360 kHz) can cause ringing in a fluid composed mostly of water. Inother words, the natural frequency of the fluid is being excited. Otherfluids which have different natural frequencies than water may beexcited at those other natural frequencies. The composition of the fluidwill determine which frequency the ion generator should operate theelectromagnetic fields of influence. A frequency greater than a fullwave at eighty kilohertz (80 kHz) may have the intended effect ofionizing the fluid and minimizing the present of biological organism inthe fluid.

When an excess of water-borne positive ions enters a fissure 351 thepositively charged ions have a phsio-chemical effect on the shale'slayered calcite 350 deposits. This mineralization alters the crystallinestructure of the encrustations that have been deposited within thatmatrix. The preferred polymorph of calcium carbonate (CaCO₃) is calledlayered calcite 350 (rhombohedral) while others polymorphs are calledaragonite (orthorhombic), and vaterite (hexagonal). Ionizing water viapulsed power at high frequencies incorporates a continuously varyinginduced electric field driven by a specific low frequency AC waveformand a periodic pulsed signal with a specific range of mid-to-highfrequencies.

The low frequency AC waveform affects the method of solid precipitationnucleation and the mode of solid precipitation crystal growth. In thisway such growth results in the precipitation but does not form onsurfaces but forms in bulk solution, using microscopic suspendedparticulate, both inorganic and organic, as seed surfaces for nucleationand particle growth. In fracturing water calcium carbonate is theprimary crystalline solid precipitated in water, and is usually asurface-nucleating scale. When exposing the fissures 351 to ionizedfluid 353, the calcium carbonate precipitate incorporates into itselfother cations in solution including magnesium, silicon, aluminum, ironand is converted into a suspended particle together with otherconstituents.

The changes in crystal nucleation kinetics, together with the resultingaragonite structure, avoids the formation of surface scale and puts thecrystalline structures into suspension as individual or coalescedparticles. A difference in the relative value of the electromotiveforces, between the higher relative positive calcium values and thelower radical values, drives the conversion from scale into suspendedparticles. The positively charged ionized water makes this selectivechange possible on the layered calcite formations surfaces when exposedby the shaped charges in subsurface shale formations. The effect is thesame for both hard and soft shale.

In another example, the calcium carbonate scale layers are physicallyopened up by the shaped charges exploding into the well bore before thepressurized water carrying positive ions are forced into the fissures351. The fissures 351 are pressurized with ionized fluid 353, therebyconveying positive ions to the exposed fissures 351. The ionized fluid353 is allowed to remain in the fracture zone 340 for a few days. Aftera period of time the pressurized ionized water is depressurized bycoiled tubing 309 and the released hydrocarbons, suspended particles352, proppant plus other materials that a person well known in the artmight expect are carried out of the fissures 351 by the flow back andproduced water from the wellbore. While in these fissures 351, thepositive ions in, for this example water, selectively interact with thelayered calcite and change their crystalline structure from calcite(rhombohedral) into the preferred aragonite (orthorhombic) polymorphcrystal form of suspended particle which the flow back water removesfrom the fissures 351.

The depressurization removes layers of encrustations or scale, depictedhere as layers of suspended particles 352, in the fissures 351 in alayered fashion and opens up the channels by permitting a faster rate ofgaseous and liquid hydrocarbons to be carried by the water flow up tothe surface. This removes bottom hole pressure of the fissures, in alayered fashion, permits a greater rate of hydrocarbon flow to beachieved initially and for a longer period of time than would otherwisebe possible. Calcium carbonate in solution exists as colloidal particlestypically in the range of 0.01-100 um, each one having an overallelectric charge known as the zeta potential. The magnitude of thispotential is the force by which each particle repels the force of likecharge. This force must be large enough to overcome the force ofparticles in approaching each other, so that Van der Waals forces bringthe particles together or coalesce.

The positive ions are carried in water together with the magnetic andelectric fields and interact with a resultant zeta force generated in adirection perpendicular to the plane formed by the magnetic and electricfield vectors. This is called the zeta principal as depicted in FIG. 31.This zeta force acts on the current carrying entity, the ion and slowsdown the suspended particles by interaction. Positively chargedparticles will move in a direction in accord with the Right Hand Rule,where the electrical and magnetic fields are represented by the fingersand the zeta force by the thumb. The negatively charged particles willmove in the opposite direction.

The result of these zeta forces on the ions is that, in general,positively charged ions like calcium and magnesium and negativelycharged ions like carbonate and sulfate are directed toward each otherwith increased velocity. The increased velocity results in an increasein the number of collisions between the particles, with the result beingthe formation of insoluble particulate matter. Once a precipitate isformed, it serves as a foundation for the further growth of thecrystalline structure or polymorph of aragonite or orthorhombic, therebycreating the particles in suspension. FIG. 31 illustrates the zetaprinciple and illustrates the Zeta Potential Effect on suspendedparticles. FIG. 31 diagrams the positioning of fields and force.

The magnitude of this Zeta Potential defines the force by which eachparticle repels particles of like charge. This Zeta Potential Force isused to overcome the particles to approach each other so that the Vander Waals forces will brings the particles together and achievecontinued growth. The induced resonating electromagnetic fields producedby the pulsed power ion generators 313, thereby reducing the zetapotential and allowing the Van der Waals forces to promote particlegrowth.

Achieving the desired effect of the zeta potential by the pulsed powersignal is shown in FIG. 31. Zeta Potential is the particle effect thatprefers one polymorph to another. This is accomplished by preventing onepolymorph from growing and until the other polymorph reaches itssaturation limit. The growing of a crystalline form that uses suspendedparticles as nucleation seeds in bulk solution also facilitates theincorporation of microbes into the suspended precipitates. This effectis called encapsulation.

The periodic pulsed signal from the ion generator 313 to the water beingionized has a micro/physical and chemical effect on the cell membranes,which is called electroporation or the chemical puncturing or rupturingof the cells which kills the micro-organisms. The pulsing signal usesthe physical principle of resonating frequencies, also referred to asharmonic frequencies or ringing frequencies, to amplify the energy thatis needed to ionize the fluid with relatively low power levels.

Ionized fluid 353 also has the ability to prevent the clogging of thefissures 351 with particles by flocculation. Ionized water in turn alsoreduces the problem of clogging due to avoiding surface nucleatedprecipitation. As a result of these interactions the rate of hydrocarbonflow will be faster from the bottom hole pressure. This will also extendthe life of a hydrocarbon well for a longer period of time and increasethe percentage of recoverable reserves from a given shale formation.This process permits a greater quantity of hydrocarbons to be extractedat faster rate of flow for both gases and liquids.

In another example, the techniques described above can be used in areentry operation for a well. A wellsite that has been perforated andfractured previously can be reentered at a later date in order to boostits production levels. In that case the ionized fluid 353 would beintroduced to a shale layer 321 by way of coiled tubing 309 in a typicalfracturing reentry operation. A perforation gun may be run into the wellto make perforations 356 at new locations. Packers 341 would be put intoplace in order to seal off new fracture zones 340. Then ionized fluid353, comprising ionized water and proppants, would be pumped down intothe formation via fracture pumps 319. The ionized fluid 353 is thenpressurized in order to create and enlarge the fissures 351 thatresulted from the perforation 356. Layers of suspended particles 352would result for the exposure of ionized fluid 353 to the fissures 351.After maintaining the pressure in the fracture zone 340 of interest, thepressure would be relieved, in this case by using coiled tubing tocompromise one or more of the packers 341. The relief of pressure wouldforce the suspended particles 352 out of the fissures 351. Such areentry job would increase the production at an already producing welland increase the overall life of the well.

It should be kept in mind that the previously described embodiments areonly presented by way of example and should not be construed as limitingthe inventive concept to any particular physical configuration. Changeswill occur to those of skill in the art from the present descriptionwithout departing from the spirit and the scope of this invention. Eachelement or step recited in any of the following claims is to beunderstood as including to all equivalent elements or steps. The claimscover the invention as broadly as legally possible in whatever form itmay be utilized. Equivalents to the inventions described in the claimsare also intended to be within the fair scope of the claims. Allpatents, patent applications, and other documents identified herein areincorporated herein by reference for all purposes.

What is claimed is:
 1. A method for increasing hydrocarbon production from a subsurface formation, the method comprising: generating ionized fluid, pumping the ionized fluid from a surface location into at least one subsurface location in a hydrocarbon well, pressuring the ionized fluid at least one subsurface location, depressurizing the ionized fluid at the perforated location, wherein at least a portion of the ionized fluid returns to the surface location containing suspended materials.
 2. The method as in claim 1, further comprising perforating and fracturing at least one subsurface location.
 3. The method as in claim 1, wherein the ionized fluid comprises positively charged water.
 4. The method as in claim 1, wherein the ionized fluid is generated by exposing water to electromagnetic fields of influence.
 5. The method as in claim 4, wherein the electromagnetic field of influence is pulsed at a full wave of up to three hundred and sixty times per second.
 6. The method as in claim 1, wherein the suspended particles include calcium based suspended particles.
 7. The method as in claim 3, further comprising recycling a portion of the flowback fluid from the well.
 8. The method as in claim, further comprising ionizing the recycled portion of the fluid.
 9. A method as in claim 1, further comprising re-entering the formation.
 10. A system for increasing hydrocarbon production from a subsurface formation comprising: means for generating an ionized fluid; means for transporting the ionized fluid from the surface into at least one fracture zone of the subsurface formation, means for pressuring the ionized fluid at the at least one fracture zone; means for maintaining the pressurize at the at least one fracture zone; means for depressurizing the ionized fluid at the at least one fracture zone; wherein a portion of the ionized fluid returns to the surface carrying suspended particles of the formation.
 11. The system as in claim 10, wherein the ionized fluid comprises at least fifty percent water by volume.
 12. The system as in claim 10, wherein said means for generating ionized fluid comprises generating electromagnetic fields of influence at a full wave frequency of up to three hundred and sixty pulses per second.
 13. The system as in claim 11, wherein the electromagnetic fields of influence eliminate the majority of the micro-organisms within the ionized fluid.
 14. The system as in claim 10, further comprising a means for adding proppant to the ionized fluid.
 15. The system as in claim 14, wherein said means for adding proppant to the ionized fluid comprises a blender.
 16. The system as in claim 10, further comprising a drill mechanism attached to the coil tubing adapted to compromise at least one packer in the well.
 17. The system as in claim 13, further comprising a means for recycling flowback fluid, wherein a portion of the recycled flowback fluid is used to generate the ionized fluid.
 18. The system as in claim 17, further comprising a means for separating the flowback into water and at least one other substance.
 19. The system as in claim 17, further comprising a means for separating the produced fluid into water and at least one other substance.
 20. A method of increasing production from a subsurface shale formation comprising: generating ionized fluid with electromagnetic fields of influence; pumping the ionized fluid into the subsurface shale formation; and exposing the previously perforated zone to ionized fluid under pressure; wherein the production from the subsurface shale increases after the ionized fluid is depressurized.
 21. The method as in claim 20, wherein previously perforated zone has been previously fractured.
 22. The method as in claim 20, further comprising fracturing the previously perforated zone.
 23. The method as in claim 20, further comprising selecting a zone to expose to ionized fluid.
 24. The method as in claim 23, further comprising perforating the selected zone.
 25. The method as in claim 24, further comprising fracturing the selected zone.
 26. The method as in claim 25, further comprising isolating the selected zone.
 27. The method as in claim 26, further comprising pressurizing the selected zone with ionized water.
 28. The method as in claim 27, further comprising holding the pressure in the selected zone for a predetermined period of time.
 29. The method as in claim 28, further comprising releasing the pressure in the selected zone.
 30. The method as in claim 29, further comprising mixing the ionized fluid with a proppant.
 31. (canceled)
 32. (canceled)
 33. (canceled)
 34. (canceled) 